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Whole House Generator Cost Calculator

The price on the box is usually less than half of what a standby generator costs installed. Set the size, fuel and connection method to see the whole invoice, broken down.

Where are you?

AWG, NEC, 120/240 V, miles and gallons — we remember this on every calculator.

What kind of generator?

A portable is wheeled out and plugged in. An air-cooled standby is a permanent unit on a pad that starts itself. Liquid-cooled sets start around 25 kW and are what you need for a large all-electric home.

Generator size

Rated output in kilowatts. If you have not sized it yet, the generator size calculator works it out from your appliances. Sets advertised in kVA multiply by 0.8.

kW
Fuel

Natural gas needs a line run and never needs refuelling. Propane needs a tank you may already have. Diesel and gasoline need no pipework at all.

How does it connect to the house?

An interlock kit is the cheapest code-compliant option: a sliding plate that makes it physically impossible to have the main breaker and the generator breaker on together. An automatic transfer switch starts the generator and switches over on its own, which is the whole point of a standby set.

Distance from generator to panel

The cable run, following the route it will actually take round the house rather than the straight line. Conductor and labour both scale with it.

ft
New gas line to run

From the meter or tank to the generator. Long runs also need larger pipe, which is the single most common reason a standby set never reaches its rated output.

ft
What does it stand on?
Permit and inspection
Local labour rates

Trade labour swings by more than a factor of two across a country. Set this against what you know local rates to be — high-cost metro areas sit near 1.4, rural areas near 0.8.

1
Rural, low cost of living
0.75–0.85
National average
1.00
Major metro
1.20–1.40
High-cost coastal city
1.40–1.60
What it costs to own

Used only for the running-cost figure. The US average is about 6 hours a year, but that average hides everything — one ice storm can be 60 hours on its own.

h/year

Your result

Installed cost

$11,968

Likely range
$10,173 – $13,763
Equipment
$7,028
Installation
$4,940
Cost per kW
$544
Running cost
$382/year
Ten-year total
$15,784

🪿 The goose says: A 22 kW air-cooled standby lands around $11,968 installed — $7,028 of equipment and $4,940 of work. Expect quotes between $10,173 and $13,763, and budget $382 a year to keep it ready.

  • Equipment is 59% of this total. The other 41% is labour, pipework, concrete and paperwork — which is why the price you see advertised for the generator itself is such a poor guide to what you will pay.

Estimate for planning only. Have any electrical work verified by a qualified electrician and installed to code — see the full disclaimer at the bottom of this page.

Where the money goes

Generator
$5,828 Air-cooled standby, 22 kW
Automatic transfer switch
$1,200 equipment
Electrical labour
$3,140 30 ft run + switch fitting
Gas line
$900 25 ft plus connection
Concrete pad
$550
Permit and inspection
$350
Total installed
$11,968 $10,173 – $13,763

Labour priced at 1.00× the national average. The range is ±15%, which is about the spread you should expect between three quotes for the same job.

What the same job costs at other sizes

Air-cooled standby on natural gas, same connection and same site work.

7.50 kW
$8,430 $1,124 per kW
14 kW
$10,016 $715 per kW
22 kW
$11,968 $544 per kW
26 kW
$12,944 $498 per kW
38 kW
$15,872 $418 per kW

Cost per kilowatt falls steeply with size, because the pad, the switch, the gas line and the labour barely change. Going one size up is almost always cheaper than going one size up later.

What it costs to own

Installed cost
$11,968
Servicing
$320/year annual service contract
Fuel
$62/year 20 h of outage
Ten-year total
$15,784
Cost per year over ten
$1,578

Servicing is the item people forget. A standby set exercises itself weekly and needs an annual oil, filter and battery service whether or not the power ever goes out; the battery itself is a consumable every three to five years.

How this generator cost calculator works

A standby generator installation is two purchases wearing one price tag. The first is the machine, which is the one you can look up. The second is everything needed to make it useful: a pad to stand on, a gas line to feed it, conductors back to the house, a transfer switch so it cannot backfeed the utility, and a permit and inspection to prove all of that was done properly.

For a typical air-cooled standby job the second half is roughly the size of the first. That ratio is why quoted generator prices and actual invoices differ so much, and why a homeowner who has budgeted from a product listing is usually shocked by the first quote.

Equipment pricing follows a straight line with size, with a fixed component for the enclosure, controller and alternator that does not shrink no matter how small the engine is. That fixed component is why cost per kilowatt falls sharply as you go up: the pad, the switch, the gas line and most of the labour cost the same for a 14 kW set as for a 22 kW one.

Everything here is a planning estimate. Real quotes vary by region, by how far the generator sits from the panel and the meter, by whether your service needs upgrading, and by how busy the installer is in the month after a storm.

  1. Step 1 Equipment equipment = base + rate × kW Portable $100 + $145/kW; air-cooled standby $460 + $244/kW; liquid-cooled $700 + $391/kW, fitted to current retail listings.
  2. Step 2 Electrical work electrical = (call-out + $18/ft × run + switch fitting) × local_rate The transfer switch adds both hardware and fitting time: $450 for an interlock, $1,400 for a whole-house automatic switch.
  3. Step 3 Gas line gas = ($350 connection + $22/ft) × local_rate Only for natural gas and propane. Long runs need larger pipe, which costs more per foot than this allows.
  4. Step 4 Site work and paperwork pad + permit, scaled by local_rate
  5. Step 5 Installed total total = equipment + transfer_switch + electrical + gas + pad + permit
  6. Step 6 Quote range low = total × 0.85; high = total × 1.15 About the spread you should expect between three quotes for identical work.
  7. Step 7 Cost of ownership ten_year = installed + (servicing + fuel) × 10 Servicing is annual whether or not the power ever fails, and the starting battery is a consumable.

Example: a 22 kW air-cooled standby on natural gas with a whole-house automatic transfer switch, 30 feet from the panel, 25 feet of new gas line, on a concrete pad with a permit, at average labour rates. Equipment is $5,828 plus $1,200 for the switch; installation is $3,140 of electrical, $900 of gas line, $550 of concrete and $350 of permit. That is $11,968 installed, with quotes likely between $10,173 and $13,763 — and the generator itself is under half of it.

Assumptions & caveats

Everything this calculator quietly assumes on your behalf. If one of these does not match your situation, the answer will be off.

  • Prices are planning estimates built from current retail listings and typical contractor rates, not quotes. Regional variation is large, and the month after a major storm is the worst possible time to buy — both the equipment and the labour go up.
  • Equipment pricing is modelled as a fixed component plus a rate per kilowatt. Real product ladders have steps and promotions that this smooths over.
  • No service upgrade is included. If your panel is 100 A, full or old, upgrading it can add $2,000 to $4,000 and is often the largest single surprise in a standby quote.
  • The gas line estimate assumes the existing meter and supply can feed the generator. A 22 kW set demands roughly 300 cubic feet an hour, and many residential meters cannot supply that alongside a furnace and a water heater without being upsized by the utility.
  • No propane tank purchase or rental is included. A 500-gallon tank is $1,500 to $3,000 to buy, or free on a supply contract.
  • Permit costs vary from nothing to over $1,000 depending on jurisdiction, and some areas require separate electrical, gas and mechanical permits for the same job.
  • The annual fuel figure charges roughly $0.14 per rated kilowatt per hour of outage, which is about what a set running at 50–60% load costs on natural gas. The generator fuel calculator does that properly from the load and fuel you actually use.
  • Running cost assumes fuel is burned only during outages, plus routine servicing. It excludes the weekly exercise cycle, which is small but not zero, and the starting battery, which needs replacing every three to five years.

Frequently asked questions

How much does a whole house generator cost installed?

A 22 kW air-cooled standby with an automatic transfer switch typically lands between $11,000 and $15,000 installed, of which roughly $7,000 is equipment. Smaller 14 kW installations run $9,000 to $12,000, and liquid-cooled sets from 30 kW up start around $18,000. The variables that move it most are the distance to your panel, whether the gas meter needs upsizing, and local labour rates.

How much is a Generac generator?

The unit alone is roughly $2,900 for a 10 kW air-cooled set, $4,850 for 18 kW and $5,800 for 22 kW, with the automatic transfer switch another $500 to $1,200 on top. Installation typically adds as much again. Treat any advertised price that does not mention the transfer switch, gas line and permit as about half the real number.

How much does it cost to install a generator?

Installation alone usually runs $3,000 to $6,000 for a standby set: electrical work back to the panel, fitting the transfer switch, running a gas line, pouring a pad and pulling permits. A portable with just an interlock kit is far cheaper at $700 to $1,200. The single biggest variable is distance — every extra foot of cable and gas pipe is billed.

Is a whole house generator worth it?

It depends almost entirely on how often your power fails and what an outage actually costs you. If you lose power for days at a time, have a well, a sump pump, medical equipment or a freezer full of food, the arithmetic works quickly. If you lose it twice a year for an hour, a $500 battery station and a portable will serve you better for a tenth of the money.

How much does a generator cost for a 2,000 sq ft house?

For a gas-heated 2,000 sq ft home, a 14 to 18 kW standby covers everything and runs $9,000 to $13,000 installed. All-electric homes of the same size need 22 to 26 kW and $12,000 to $16,000, because electric heat, an electric water heater and a well pump together are more load than the floor area suggests. Square footage is a weak guide — what matters is whether heating and hot water are electric.

Do I need a transfer switch?

Yes, for anything connected to your house wiring, and it is a legal requirement under NEC 702 rather than a recommendation. Without one, a generator can backfeed the utility line and electrocute the crew repairing it. An interlock kit at $250 plus fitting is the cheapest compliant option; a full automatic transfer switch is $1,200 plus fitting.

What is the cheapest way to power my house in an outage?

A 7,500 W portable plus a panel interlock kit — roughly $2,000 to $3,000 all in, most of it the electrician rather than the generator — covers the essentials of most homes including hardwired circuits. You lose the automatic start and have to refuel it every eight hours or so, but it does about 80% of what a standby set does for around 15% of the money. Start there unless your outages are frequent enough to make the convenience worth paying for.

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Safety disclaimer

These are planning estimates, not quotes. Generator installation is regulated work: connecting a generator to house circuits requires a transfer switch or interlock installed by a licensed electrician under NEC 702, gas pipework must be sized and pressure-tested by a qualified fitter, and most jurisdictions require permits and an inspection. Backfeeding a generator through an outlet is illegal and can kill utility crews.